In the manufacture of a conventional ferro-electric liquid-crystal panel for an indicator, upper and lower substrates have electrodes and alignment layers processed by rubbing and the like and a liquid crystal is placed between the substrates. In order to align the liquid crystal uniformly, the alignment direction of one of the alignment layers is parallel, but opposite (180 degrees) to that of the other alignment layer.
It is well known that a ferro-electric liquid-crystal panel can function as a sound generating device. When alignment directions of two alignment layers are opposite (180 degrees), however, a ferro-electric crystal-liquid panel is not suitable for use as a sound generating device. In order for such a ferro-electric liquid-crystal panel to properly generate sound, the alignment direction of one of the two alignment layers must be at right angles to that of the other electrode base plate. With this arrangement, however, the panel can not be used as an indicator.
As explained above, since a conventional ferro-electric liquid-crystal panel can not be used both as an indicator and a sound generating device, panels have to be designed either as an indicator or as a sound generating device according to their intended use, and this is not efficient.